Four main elements of surveillance cameras

Whether purchasing or commissioning surveillance camera, you must know the four main points of surveillance cameras: the maximum aperture, focal length, close-up ability, expressive ability.

First, the maximum aperture:

The real value of the maximum aperture performance is the amount of light in increasing low light situations, so achieve the best combination of exposure. Generally it is not required the virtual camera capabilities when you take landscape photography, in addition, the dark places are also not very demanding lens diameter. However, when the 70-200mm zoom lens leaving the installation of 2 times teleconverter and telephoto focal length becomes 400mm auto-focus with AF, the best choice for the maximum aperture of the IP camera is F2.8 lens. The large aperture is conducive to accurate focusing in dark conditions. Use a large diameter lens to recording someone even in low light, it also can shoot handheld use of natural light. In addition, a large maximum aperture of the lens can bring a faster shutter speed, so sports photography requires a large aperture lens.

Second, the focal length:

The first note of choosing the lens is that the lens focal length, in fact, it is actually viewing angle, different focal length of surveillance camera, perspectives are different. So you must be clear, What is the main purpose you purchase a lens? In order to shot landscape or figure and so on? As we all know, making scenery suitably use the wide-angle lens , and shooting the figure is appropriate to use the best telescope, so we must according to the purpose of taking photography to determine which focal length of the lens we should to buy.

Third, close-up ability:

Lens close-up ability is third element except focal length, maximum aperture. This is the same both for the wide-angle lens, standard lens or a telephoto lens. So, how much close-up ability would be suitable?

For example, the wide-angle lens which is used to landscape photography, the close-up ability is almost nothing for wide angle lens, but when shooting broad landscapes to flowers as the background scenery, it is often necessary to photograph flowers larger, then wide-angle lens in a similar case of close-up ability becomes very important.

When you select the lens, you must know how the image sharpness of this lens. The usage of photo determines what kind the sharpness of the lens. High-quality lens is mainly used by professional photographers, if only the general photography, there is no need to spend a lot of money to buy high quality lenses. In addition, the imaging lens sharpness also has a direct relationship with aperture size, when a lens is two steps from maximum aperture, it will be stopped down one and then the image sharpness will be greatly improved.